I've been eating a lot of Korean barbecue lately and there is something that I keep noticing.

You can find these buttons on the tables of practically every K-Town, as Koreatown is affectionately called, barbecue joint. A bit of journalistic research (tapping the button during a meal) led me to discover their purpose: to call over the server.

Duh, right? That's what some of you are probably thinking. And it's what my Angeleno friends told me. But I'm new to the city and I was curious: Where did these call buttons come from? Why are they so popular at Korean barbecue joints? These questions took me straight to David Kang, head of the Korean Studies Institute at the University of Southern California.

"These call buttons are relatively new," Kang told me. "In Korea it's still common that, if you want something, you yell' yogi-yo' or 'here!' and you wave your arm. Then they come running over and they're like, "what do you want?"

Call buttons have only become common to Koreatown in the last generation or so, Kang says, as non-Koreans increasingly began to venture into Korean restaurants. He says they are the product of two very different dining cultures.

"The American internal logic is the waiter comes over, they introduce themselves, they're friendly, they keep checking up on you. The Korean internal logic is, you're there to eat. And [the waitstaff] don't bother you unless you call them over."

The restaurant Park's BBQ serves exquisite grilled meat out of a strip mall in Koreatown. The facade is a little grimy, but on a Wednesday afternoon the parking lot is packed with BMWs and Mercedes. David Chang, a server at Park's BBQ, says that people ask about the call buttons all the time it's a sign they might be tourists.

"They are like, 'What does this do?' "Chang says. "Or sometimes they press it and I go over there and they are like 'I don't know what this was for,' and I am like, 'So you just... pressed it?' "

Jake Ayers was visiting from Seattle when I caught up with him at Park's BBQ. He didn't know what to do with the button on his table. But when I told him what it was for, he gave it a try.

Then he tried it again.

That's a faux pas says David Chang, the server at Park's BBQ. He has this advice for K-town newbies: Definitely hit the call button when you need something. But then just wait. Don't hit it again.